What is the point of on-board fuel reforming?

On-board autothermal reforming, which had been intended for mobile fuel cell applications, has evolved into exhaust gas reforming-a technology that could make it more difficult for the internal combustion engine to be displaced. Among the technical barriers that prevented implementation of fuel cell drivetrains based on autothermal reforming was the integration of several chemical processes into an energy-and space-efficient system with a high degree of heat management. By contrast, an exhaust gas reformer bears much more resemblance to the passive catalytic converters used for exhaust-gas after treatment, except that it is located in a recirculation loop close to the engine. When the reactions are predominantly endothermic, the reformer recovers waste heat and generates reformate with a higher fuel heating value than that of the fuel it consumes. The reformate does not need any further treatment, but can be fed directly to the engine, where it will have an additional impact on fuel economy by acting as a gas-phase combustion promoter. On-board reforming also increases the number of potential after treatment options, some of which are substantially improved by the addition of hydrogen.